Project: Capillary Break Beneath a Slab: Polyethylene Sheeting Over AggregateTechnology Focus: Foundation, water managementProfile: In this project, IBACOS worked with a builder of single- and multifamily homes in southwestern Pennsylvania (climate zone 5) to understand its methods of successfully using polyethylene sheeting over aggregate as a capillary break beneath the slab in new construction.

Project: Cladding Attachment Over Mineral Fiber Insulation BoardTechnology Focus: Exterior insulation of wood-framed buildings, new and existing homesProfile: In this project, Building Science Corporation studied the performance of mineral fiber insulation sheathing as a viable solution for exterior insulation retrofits, and developed guidance for retrofit assembly for wood-frame roof and walls and for cast concrete foundations.

Project: Cold Climate Foundation Wall Hygrothermal Research FacilityTechnology Focus: Building envelope and wall systemsProfile: This case study describes the University of Minnesota’s Cloquet Residential Research Facility in northern Minnesota, which features more than 2,500 ft2 of below-grade space for building systems foundation hygrothermal research.

Project: High-Performance Walls in Hot-Dry ClimatesTechnology Focus: WallsProfile: In this project, the Alliance for Residential Buildng Innovation team worked with California builders to to implement wall assemblies meeting a U-value lower than 0.050 Btu/h-ft2-°F. The team observed and documented construction methods and obtained construction costs from builders to inform cost estimates for a range of advanced wall system types and insulation types.

Project: Moisture Management of High-R WallsTechnology Focus: Exterior insulation, existing homes with vapor open wall assembliesProfile: This project by the Building Science Corporation team focuses on how eight high-R walls handle the three main sources of moisture—construction moisture, air leakage condensation, and bulk water leaks.

Project:Preventing Thermal BypassTechnology Focus: Fully aligned air and thermal barriersProfile: This project highlights the importance of continuous air barriers in full alignment with insulation to prevent thermal bypasses and achieve high energy performance, and recommends use of ENERGY STAR's Thermal Bypass Inspection Checklist.

Project: Project Overcoat: Airtightness Strategies and Impacts for 1-1/2 Story HomesTechnology Focus: Building envelope; roof/attic air seal and insulationProfile: The NorthernSTAR team studied the effectiveness of the External Thermal Moisture Management System as a solution for improving airtightness in a roof-only application and compared the results to more than 250 roof-only, interior-applied energy retrofits on 1-½ story homes.

Project: Stand-Off Furring in Deep Energy RetrofitsTechnology Focus: Exterior wall envelopeProfile: This research project, conducted by IBACOS and GreenHomes America, investigated cost-effective deep energy retrofit solutions for improving the building shell exterior while achieving a cost-reduction goal, including reduced labor costs to reach a 50/50 split between material and labor..

Project: Taped Insulating Sheathing Drainage PlanesTechnology Focus: Building envelopeProfile: The energy efficiency-based financial benefits of adding exterior insulation are well accepted by the building industry, and using exterior insulation as the drainage plane is the next logical step. This project by Building Science Corporation focuses on the field implementation of taped board insulation as the drainage plane in both new and retrofit residential applications.

Project: Ducts in Conditioned Space in a Dropped Ceiling or Fur-downTechnology Focus: HVAC systems, ductsProfile: This case study examines an inexpensive, quick and effective method of building a fur-down or dropped ceiling chase, which brings the duct system into the interior of the house to reduce air leakage and improve durability and indoor air quality homes.

Project: Raised Ceiling Interior Duct SystemTechnology Focus: HVAC systems, ductsProfile: This project describes a Habitat for Humanity builder’s efforts to construct a home to new DOE Zero Energy Ready Home standards using a fur-up or raised ceiling chase.

Project: Sealed Air Return Plenum RetrofitTechnology Focus: HVAC systemsProfile: In this project, Pacific Northwest National Laboratory researchers greatly improved indoor air quality and HVAC performance by replacing an old, leaky air handler with a new air handler with an air-sealed return plenum with filter; they also sealed the ducts, and added a fresh air intake.

Project: Foundation Heat ExchangerTechnology Focus: HVAC and water heatingProfile: The foundation heat exchanger, developed by Oak Ridge National Laboratory, is a new concept for a cost-effective horizontal ground heat exchanger that can be connected to water-to-water or water-to-air heat pump systems for space conditioning as well as domestic water heating.

Project: Ground Source Heat Pump Research, TaC Studios ResidenceTechnology Focus: Heating and cooling systemsProfile: This case study describes the construction of a new test home that demonstrates current best practices for the mixed-humid climate, including a high performance ground source heat pump for heating and cooling, a building envelope featuring advanced air sealing details and low-density spray foam insulation, and glazing that exceeds ENERGY STAR requirements.

Project: Overcoming Comfort Issues Due to Reduced Flow Room Air MixingTechnology Focus: HVAC equipmentProfile: In this project, IBACOS studied when HVAC equipment is downsized and ducts are unaltered to determine conditions that could cause a supply air delivery problem and to evaluate the feasibility of modifying the duct systems using minimally invasive strategies to improve air distribution. .

Guides for All Climates

DOE has developed several Best Practices guidebooks that are applicable across all climate regions.

For additional, updated information on hundreds of building science topics that can help you build or retrofit to the most recent high-performance construction criteria, including the latest version of ENERGY STAR and the DOE Challenge Home requirements, see the Building America Solution Center.